When used correctly, light therapy can help alleviate the fatigue and decreased activity commonly experienced in the shorter days of fall and winter, or even into spring. It is a common treatment for SAD. (seasonal affective disorder or "winter blues").

Seasonal Affective Disorder: What Is It?

Seasonal Affective Disorder or SAD (sometimes called winter depression) is a condition characterized by recurrent depression in the fall and winter months, which alternates with nondepressed times in the spring and summer. In fall and winter, people with SAD usually experience an increase in vegetative symptoms including oversleeping, overeating, carbohydrate craving weight gain, fatigue, and social withdrawal. Many people with SAD note a marked responsiveness to changes in climate, latitude, and light conditions. Mood may lighten and energy may increase when a person with SAD spends more time in areas with windows or when the weather improves. Mood and energy may deteriorate when the amount of environmental light is reduced.

How Can Light Therapy Help?

Regular exposure to light of sufficient intensity, even artificial light, has been shown to ameliorate the symptoms of SAD for some people. Regardless of the mechanism, the findings that light therapy is a viable treatment for winter depression are widely supported.

People who are responsive to light therapy will generally see some effect after a week of treatment, although two weeks of treatment or more produces the greatest effects. Morning exposure has been shown to be somewhat better at achieving relief of symptoms than evening exposure. The symptoms most likely to respond to light treatment include: hypersomnia (oversleeping), carbohydrate cravings, afternoon and evening "slumps," and reverse diurnal variation, where evenings are worse than mornings. Symptoms less likely to be responsive include melancholic symptoms, suicidality, appetite loss, feelings of guilt, insomnia, and typical diurnal pattern, where mornings are worse than evenings.

What are Possible Side Effects?

Although negative side effects are uncommon, people sometimes complain that light therapy causes irritability, eyestrain, headaches, sleep disturbances or insomnia. The latter is most likely to occur when people use the light source in the evening. Mild visual side effects are common but remit promptly. Side effects can generally be reversed by decreasing the duration of treatment or increasing the distance between the patient and the light source.

FOR MORE INFORMATION ON LIGHT THERAPY AND SEASONAL AFFECTIVE DISORDER:Web MD

APPOINTMENT LENGTHBegin with 15-minute sessions and adjust to your needs to alleviate your symptoms, up to 40 minutes. Daily use is suggested. The timing of the treatment is usually based on your sleep cycle. Those who experience SLEEP PHASE DELAY (that is, you struggle to wake up in the mornings) are advised to use the light as early in the day as possible. Those who experience SLEEP PHASE ADVANCE (that is, you fall asleep too early in the evening) are advised to use the light between 3 and 5 pm.

ADJUSTING TO LIGHT INTENSITYSome individuals prefer to get used to the brightness of the light before their therapy session. This can be achieved by turning it on for several minutes before sitting directly in front of it, allowing your eyes to adjust more comfortably. Light intensity is 10,000 lux which is about the brightness of a cloudy day in Alaska, mid-winter.

You will need to sit 12 to 16 inches away from the light. DO NOT STARE DIRECTLY INTO THE LIGHT but also do not wear sunglasses. Reading a book/magazine, using a laptop computer, doing homework, etc., in front of the light is a great way to get the full effect.

IMPORTANCE OF REGULAR USEConsistency of use is important in reducing the symptoms of Seasonal Affective Disorder. Try it for at least two weeks to experience relief and afterwards on a semi-regular basis (every other day or three times a week) as long as symptoms persist. If you miss sessions or discontinue use of the light, your body will return to its usual state. Your energy should return within a few days of resuming use.

SYMPTOMS OF OVERUSEAlthough there are rarely any negative side effects of using light therapy, it is possible to use the light too much. If you experience irritability, excessive energy, and/or any discomfort consistently during or after use, decrease the length of your sessions or move the light several inches farther away from you.

WARNINGThe guidelines outlined here are applicable for SAD, the winter blues, and supporting general well-being. Do not use the light for relief of any other type of mood disorder without the close supervision of a health professional. If you suffer from a mood disorder such as depression, are on prescription medications that react with sunlight, such as certain antibiotics or anti-inflammatories, your skin is sensitive to light, you have a history of eye conditions or you are under medical care for any reason, please consult your health professional before using. If you are currently engaged in counseling or therapy, you should consult your mental health professional prior to use. If you begin to experience any negative side effects, check with the CSB/SJU Counseling and Health Promotion staff.